This python module implements an audio codec IMA ADPCM suitable for use in games or other audio applications. It support 256 bytes compressed blocks with 505 4-bit samples at sample rate 8 KHz mono and 1010 bytes uncompressed blocks with 505 16-bit samples at sample rate 8 KHz mono. 16-bit data samples encoded as 4-bit differences result in 4:1 compression format.